Concrete plank mold for a molding machine

ABSTRACT

A concrete plank mold including a bottom with a flexible grooveforming strip and sides tiltable relative to the bottom can be moved into and out of a molding machine on rollers. Plates swingable by fluid-pressure jacks at opposite sides of the mold are securable by latch jacks to the mold sides. Tapered mold end plates are held against the ends of the mold sides to confine the material in the mold during swinging of the mold sides to settle the concrete mix.

United States Patent [191 Draughon et a1.

[ May 28, 1974 CONCRETE PLANK MOLD FOR A MOLDING MACHINE [76] Inventors: Roland C. Draughon, 2922 S.

Adams, Tacoma, Wash. 98409; Paul D. Jensen, 101 l-68th Ave. E., Tacoma, Wash. 98424; Donald E. Jensen, 1005 Fife Heights Dr. N.E., Tacoma, Wash. 98422 221 Filed: Apr. 17, 1972 21 Appl. No.: 244,661

Related US. Application Data [63] Continuation-impart of Ser. No. 822,506, May 7,

1969, Pat. NO. 3,664,792.

[52] US. Cl 249/50, 249/99, 249/112, 249/167, 249/170 [51] Int. Cl.....+ E04g 11/50 [58] Field of Search 249/50, 98, 99, 109, 101, 249/112, 155, 160-167, 170, 171; 425/62,

[56] References Cited UNITED STATES PATENTS 1,423,708 7/1922 B unn 249/50 1,752,671 4/1930 Knight 249/98 X 2,798,373 7/1957 Harza 249/98 X 3,010,174 11/1961 McCall 249/50 3,704,852 12/1972 Wellander 249/50 Primary Examinerl. Spencer Overholser Assistant ExaminerDeWalden W. Jones Attorney, Agent, or Firm-Robert W. Beach [57] ABSTRACT A concrete plank mold including a bottom with a flexible groove-forming strip and sides tiltable relative to the bottom can be moved into and out of a molding machine on rollers. Plates swingable by fluid-pressure jacks at opposite sides of the mold are securable by latch jacks to the mold sides. Tapered mold end plates are held against the ends of the mold sides to confine the material in the mold during swinging of the mold sides to settle the concrete mix.

8 Claims, 9 Drawing Figures PATENTEDMY 28 m4 SHEH N (If 4 l CONCRETE PLANK MOLD FOR AMOLDING MACHINE This application is a continuation-in-part of our United States Patent application Ser. No. 822,506, filed May 7, 1969, for Concrete Plank Molding Machine issued May 23, 1972 as US. Pat. No. 3,664,792.

While the mold of the present invention could be used for molding various types of elongated concrete articles, it is particularlyadvantageous for molding concrete planks having tongue and groove edges so that such planks can be assembled in interfitting relationship to form a wall. Preferably the interfitting tongues and grooves are of dovetail cross section so that the adjacent planks will be locked together.

A principal object of the present invention is to provide a mold which can be used effectively in a production-line type of operation so that the mold can be moved quickly into the molding machine, charged with concrete mix, the concrete mix can be worked in the mold so that the mold is filled completely and the mold can then be locked up and removed from the molding machine for curing of the concrete.

A related object is to provide a mold which can be stripped readily from the molded product.

Another object is to provide a simplified mold structure which will be rugged in use, the parts of which can be assembled readily.

FIG. 1 is a side elevation of the concrete molding machine with a mold in place in it, parts being broken away. FIG. 2 is an end elevation of such molding machine and mold showing parts in one relationship and FIG. 3 is an end elevation of the molding machine and mold showing parts in a different relationship.

FIG. 4 is a plan of the molding machine and mold.

FIG. 5 is an enlarged vertical transverse section through the mold and adjacent portions of the molding machine showing parts in one relationship and FIG. 6 is a similar view showing parts in a different relationship.

.FIG. 7 is a top perspective of an end portion of a mold and adjacent parts of the molding machine, portions being broken away.

FIG. 8 is an enlarged transverse section througha preferred type of mold containing a molded concrete product, and FIG. 9 is a similar view with most of the mold parts stripped from the molded product.

While the molding apparatus of the present invention is illustrated in connection with only one general type of mold form, it will be appreciated that molds of different shape can be used with the molding machine. Such machine is, however, particularly well adapted to be used for producing tongue and groove planks in molds of the type shown in the drawings and described below. The representative plank mold includes elongated side plates 1 having downwardly and inwardly inclined lower flange. portions 2 and inclined mold top portions 2' which are adapted to mold V-joint plank edges. Upper edge flanges 1 flare upwardly from the adjacent portions of the side plate tops to provide a form for a dovetail tongue. Such side plates extend upward from an elongated bottom plate 3 which preferably has an arched central portion and flanges 4 flaring upwardly generally complementally to the inclination of the lower side'plate flanges 2. The arched central portion of the bottom plate and its side flanges cooperate to form a plate having a cross section of shallow W- shape providing spaced grooves in which the lower side ering bottom plate 3 and having edge portions engaged between the lower flanges 2 of the side plates and the edge flanges 4 of the bottom plate to provide a seal between such flanges in overlapping relationship. The

side portions 6 of the liner can be bonded to the mold bottom plate 3. The central portion 5 of such liner is molded or otherwise shaped as a hollow bulge having undercut side portions to form, in its relaxed condition, a groove of generally dovetail shape in a molded plank edge. Such liner bulge 5 is sufficiently flexible so that it may be deformed to be stripped out of the narrow opening of the molded groove.

The opposite ends of the mold are closed by end plates 7 which may be tapered in profile toward the mold bottom plate 3. The lower portion of each end plate is secured to the adjacent end portion of the mold bottom plate by a bolt 8 extending through the end plate and screwed into a nut 9 secured to the bottom plate. As seen in FIGS. 1, 5 and 6, such bolt extends into the hollow within the bulge 5 of the bottom liner so that these bolts do not interfere with production of the molded product. The upper portions of the end plates are wide enough so that they will close the ends of the mold even when the side plates are tilted outward through a substantial angle from their parallel relationship as shown in FIG. 6. Also, each end plate has in it a central aperture 10 for the purpose of receiving an end portion of a core tube 11 extending lengthwise of the mold. Such core tube may be disposable, being made of cardboard, or may be contractable for removal from a molded product.

The molding machine has side presser and backing plates 12yconfining opposite sides of the mold, respectively, as shown best in FIGS. 5 and 6. These plates are supported by presser blocks 13 shown in FIGS. 5, 6 and 7, the lower ends of which blocks are mounted on pivots 14 extending between parallel upright mounting plates 15. The backing plates 12 are capable of exerting pressure uniformly along their lengths on mold side plates 1 which they engage because they are backed by strongback bars 16 extending along their upper portions and connected to the presser blocks 13.

Pressure is exerted on the backing plates at the locations of the strongback bars by fluid-pressure jacks l7 shownin FIGS. 2, 3, 8 and 9. These jacks are tiltably mounted by pivots 18 carried by the mounting plates 15 and their bases are connected by bars 17 to coordinate swinging of the jacks. The jack plungers 19 are connected by pivots 20 to yokes 21 mounted on the strongback bar 16 as shown in FIGS. 5, 6 and 7. The axes of pivots 18 are located so that the jack plungers will be disposed substantially perpendicular to backing plates 12 when the jacks are exerting the greatest pressure on such plates.

In'order to allow the opposed backing plates 12 to be spread apart sufficiently to enable a mold to be moved between them, the presser mechanism including a plate l2, presser blocks 13 and strongback bar 16 should be capable of being swung outward about the pivot 14 into the position shown inFIG. 5. With the presser mechanism parts in this position, the lower portions of the presser blocks will be spaced apart a distance greater than the width of the mold end plate 7 between them as shown in FIG. 5. When a mold has thus been positioned between the presser plates 12 jacks 17 can be extended to swing the pressure mechanism from the positions shown in FIG. 5 in full lines into the positions shown in FIG. 6 in full lines.

During the molding operation the backing plates 12 should not be permitted to separate more than shown in full lines in FIG. 6. To limit movement of the backing plates to this range holes 22 are provided in the pressermounting plates 15, as shown in FIG. 5, through which stop rods 23 can be projected so as to be engaged by presser blocks 13 as limit stops. Such rods can be projected through the apertures 22 by fluid-pressure jacks 24 shown in FIGS. 4, 7 and 8. The location of the stop rods and stop-rod holes will be selected in accordance with the type of mold being used in the molding machine. It would be possible to provide more than one set of fluid-pressure jacks 24 and stop rods corresponding to molds of different types if desired.

The elongated molds are conveyed into the molding machine on a roller conveyor having rollers 25, which can bev idler rollers or live rollers as may be preferred. The axles 26 of such rollers are journaled in bearing blocks 27 mounted on longitudinal beams 28 of the molding machine frame. Such beams are supported by posts 29 from a mobile base 30. Itis preferred that the base be of the mobile type so that the molding machine can be transported easily fromone job location to another, but it is not necessary to the functioning of the apparatus for it to be of mobile type.

As has been mentioned above, the mold is conveyed into the molding machine on the roller conveyor when the backing plates 12 have been spread to the relationship shown in full lines in FIG. 5 so that the mold end plates 7 can pass between the backing plates. As shown in FIG. 4 the mold end plates 7 are spaced apart a distance just slightly exceeding the lengths of the backing plates 12 and strongback bars 16. When the forward end plate 7 ofthe mold has passed beyond the backing plates and strongback bars, therefore, such bars and plates can be tilted inward from the full-line position shown in FIG. 5 to the full-line positions of FIG. 6. The mold will then be in a position relative to the molding apparatus for performance of a molding operation.

To hold the mold in this position, mold end positioning plates 31 may be swung about their supportingpivots 32 from retracted downwardly-swung positions, shown in broken lines at the left of FIG. 1 and in FIG. 4, upward into the full-line positions of FIGS. 1, 4, 7 and 8. Such swinging is effected by actuation of jacks 33 mounted at opposite ends of the molding apparatus on pivots 34 supported by hangers 35 as indicated in FIGS, 2, 3 and 8. Each jack plunger 36 is connected to its mold end positioning plate by a pivot 37. Each holding plate 31 has adjusting screws 38 threaded through it which are engageable with the corresponding mold end plate 7. Adjustment of such screws can be effected to insure that even pressure will be transmitted from the positioning plate to the mold end plate.

When the mold has been positioned in the molding machine and the backing plates 12 have been moved into positions between the end plates 7 as shown in full lines in FIG. 6, the backing plates may be connected respectively to the mold side plates 1 when the backing plates have been moved into contiguous backing contact with such mold plates as indicated in broken lines in FIG. 5. The connection between the backing plates and mold side plates is effected by actuation of latching jacks 39 to project the latch plungers 40 downward to engage in holes 41 provided in lugs 42 welded onto the mold side plates. Thereafter, positioning and movement of the mold side plates can be placed under the control of the backing plates 12 if the side platesecuring rods 43 are withdrawn from the apertures 44 in the end plates 7 shown in FIG. 6, or are at least re tracted sufficiently so that the upper side plate flanges 1 will be able to pass the ends of rods 43. Otherwise engagement of the mold side plate upper flanges 1 with the rods 43 will hold such side plates from being spread apart from the position indicated in full lines in FIG. 5 and in broken lines in FIG. 6.

In operation a mold is conveyed by the rollers 25 of the roller conveyor into the molding apparatus between the spaced backing plates while they are spread apart by the jacks 17 to their position shown in FIG. 5. When the mold has been moved into the molding apparatus to a position in which the backing plates 12 will pass between the mold end plates 7, the jacks 17 are actuated to swing the backing plates from the solid-line position of FIG. 5 into the broken-line position of that figure. Next the latch jacks 39 are actuated to engage the latch pins 40 in the apertures 41 of lugs 42 so that the backing plates and the mold side plates are interconnected for conjoint movement. The mold side-securing rods 43 are then withdrawn to free the mold side plates 1 for movement relative to the mold end plates 7.

With the mold side plates 1 thus freed for tilting relative to the mold end plates 7, the stop rods 23 are projected into the apertures 22 of the presser-mounting plates 15 to limit the extent of outward swinging of the backing plates 12. The jacks 17 may then be actuated to swing the backing plates and mold side plates 1 from the broken-line positions of FIG. 6 to the solid-line positions of that figure. If a core tube 11 has not yet been placed in the mold form, such tube is next inserted and the mold end positioning plates 31 are swung from their retracted positions shown in broken lines in FIG. 4 into their holding positions shown in full lines in FIG. 1 by actuation of jacks 33. The mold is now ready to receive concrete mix.

In order to settle the concrete mix in the mold the jacks 17 may be extended and retracted several times to swing the backing plates 12 and mold side plates 1 inward from the solid-line positions shown in FIG. 6 and back outward. On the final stroke the jacks 17 are extended sufficiently so that the backing plates 12 force the mold side plates 1 inward to the broken-line positions shown in FIG. 6. In such positions the side plate-securing rods 43 can be projected through the apertures 44 into the positions shown in FIGS. 4 and 7 so that the upper side wall flanges 1' will bear against such rods and hold the mold side walls against outward swinging.

The latching jacks 39 can next be actuated to retract their plungers 40 from the apertures 41 in the mold sides to disconnect the backing plates from the mold side plates 1. Cylinders 24 can then be actuated to withdraw stop rods 23 from their apertures in plates 15, after which jacks 17 can be retracted to swing the backing plates 12 and other portions of the presser mechanism into the solid-line positions shown in FIG. 5. When the jacks 33 have been retracted to swing the mold-end positioning plates 31 from their upright positions into their lowered retracted positions shown in broken lines in FIG. 4, the filled mold can be rolled out of the molding machine on the rollers 25 of the roller conveyor and the next mold can be rolled into place in the machine to be filled.

When the filled mold has been removed from the molding machine it can be transported to a curing room where it will remain until the concrete has set. After the concrete has set the mold end plate-securing rods 43 can be withdrawn and the upper flanges l of the mold sides can be pressed apart, which will serve the double function of stripping such side plates from the sides of the molded plank and of causing the mold side flanges 2 to raise the bottom of the molded plank to strip it from the liner 6. The molded plank can then be hoisted from the mold to pull its dovetail bottom groove off the flexible liner central bulge 5. Now the mold can be reassembled and the securing rods 43 projected through their apertures 44 again to restore the mold to its assembled condition to be returned to the molding machine.

In FIG. 8 a mold similar to that shown in FIGS. 5 and 6 is illustrated but having somewhat different features. The mold side plates 1 having upper flanges 1' differ from the side plates of the mold shown in FIG. 5 by having horizontal flat shoulders with upwardly inclined portions 1" joining the sides proper and the upper flanges 1', so that the shoulders on the tongue edge of the molded plank will be more similar to the margins of the undercut cavity formed on the opposite edge of the plank.

The flexible sheet liner forming the opposite or lower edge of the molded product is made of stiff resilient material having the central bulge 5 joining portions which are curved more gently than the corresponding portions of the liner shown in FIG. 5. The side portions of the liner, instead of being simply of angle shape, have flat portions 6' adjacent to their edges and joining inner flat portions 6 and outer margin portions 6" at angles, as shown best in the lower right portion of FIG. 9. The opposite flat horizontal band portions 6' are disposed in substantially coplanar relationsip.

The lower mold plate has inclined edge flanges 4 which are joined to the central portion of such bottom plate by horizontal flat sections 4 that are not included in the mold bottom plate shown in FIGS. 5 and 6. Such flat band portions are disposed in substantially coplanar relationship. The liner flat band portions 6 and the bottom plate flat band portions 4' will result in the formation of flat bands on opposide sides of the reentrant cavity of the molded product which will match the corresponding coplanar spaced parallel band portions of shoulders at opposite sides of the tongue of an adjacent similar molded plank.

The sheet liner 5, 6, 6, 6 is sufficiently flexible so that after the side plates 1 of the mold have been re,- moved from the molded plank and the molded plank has been removed from the mold bottom plate, the liner can be stripped out of the reentrant groove extending along the edge of the plank in the manner indicated in the bottom left portion of FIG. 9.

We claim:

1. A mold for molding elongated concrete products comprising a bottom plate having upwardly flaring edge flanges, end plates at opposite ends of said bottom plate, opposite side plates between said end plates and having lower inwardly and downwardly inclined flanges settable on the flaring flanges of said bottom plate, and means interengageable between the upper portions of said end plates and the upper portions of said side plates for limiting separating movement of the upper portions of said side plates.

2. The mold defined in claim 1, in which the opposite side plates have inwardly-extending top portions and upwardly-directed flanges extending along and up- -wardly from the inner parts of said top portions, and

the interengageable means includes rods connected to the end plates and engageable behind said upwardlydirected flanges of the opposite side plates for engagement with said flanges.

3. The mold defined in claim l, and a flexible liner overlying the mold bottom plate, having edge portions received between the bottom plate edge flanges and the lower side plate flanges, and having a central portion bulged upwardly above the central portion of the bottom plate.

4. The mold defined in claim 3, in which the upwardly-bulgedcentral portion of the flexible liner is hollow and has undercut side portions.

5. The mold defined in claim 3, in which the flexible liner has substantially flat band portions adjacent to its opposite edges, which band portions are disposed in substantially coplanar relationship.

6. A mold for molding elongated concrete planks comprising a bottom plate having upwardly flaring edge flanges, opposite side plates having lower inwardly and downwardly inclined flanges settable on said upwardly flaring flanges of said bottom plate, means for closing the opposite ends of the mold, and corresponding pairs of coplanar parallel band portions along opposite sides of said mold, said band portions of one pair being formed by said bottom plate inwardly of said upwardly flaring edge flanges, for forming along the opposite edges of the molded plank spaced coplanar parallel bands for matching corresponding bands on adjacent plank edges.

7. The mold defined in claim 6, in which the opposite side plates of the mold have inwardly-extending top portions and upwardly-directed flanges extending along and upwardly from the inner edges of said top portions, and said inwardly extending top portions include one pair of coplanar parallel band portions.

8. The mold defined in claim 6, and a flexible liner overlying the mold bottom plate, having edge portions received between the bottom plate edge flanges and the lower side plate flanges including a pair of coplanar parallel band portions, and having a central portion bulged upwardly above such pair of coplanar parallel band portions.

mg UNITED STATES PATENT OFFICE CERTIFICATE GE QORRECTION Patent No. 3,813,076 I Dated May 28, 1974 I ofl Roland C. Draughon, Paul D. Jensen, Donald P. Jensen It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

I" Title page, under section 76, change "Donald E. Jensen" to -Donald P. Jensen.

Signed and sealed this 29th day of October 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of 'Patents 

1. A mold for molding elongated concrete products comprising a bottom plate having upwardly flaring edge flanges, end plates at opposite ends of said bottom plate, opposite side plates between said end plates and having lower inwardly and downwardly inclined flanges settable on the flaring flanges of said bottom plate, and means interengageable between the upper portions of said end plates and the upper portions of said side plates for limiting separating movement of the upper portions of said side plates.
 2. The mold defined in claim 1, in which the opposite side plates have inwardly-extending top portions and upwardly-directed flanges extending along and upwardly from the inner parts of said top portions, and the interengageable means includes rods connected to the end plates and engageable behind said upwardly-directed flanges of the opposite side plates for engagement with said flanges.
 3. The mold defined in claim 1, and a flexible liner overlying the mold bottom plate, having edge portions received between the bottom plate edge flanges and the lower side plate flanges, and having a central portion bulged upwardly above the central portion of the bottom plate.
 4. The mold defined in claim 3, in which the upwardly-bulged central portion of the flexible liner is hollow and has undercut side portions.
 5. The mold defined in claim 3, in which the flexible liner has substantially flat band portions adjacent to its opposite edges, which band portions are disposed in substantially coplanar relationship.
 6. A mold for molding elongated concrete planks comprising a bottom plate having upwardly flaring edge flanges, opposite side plates having lower inwardly and downwardly inclined flanges settable on said upwardly flaring flanges of said bottom plate, means for closing the opposite ends of the mold, and corresponding pairs of coplanar parallel band portions along opposite sides of said mold bottom plate inwardly of said upwardly flaring edge flanges for forming along the opposite edges of the molded plank spaced coplanar parallel bands for matching corresponding bands on adjacent plank edges.
 7. The mold defined in claim 6, in which the opposite side plates of the mold have inwardly-extending top portions and upwardly-directed flanges extending along and upwardly from the inner edges of said top portions, and said inwardly extending top portions include one pair of coplanar parallel band portions.
 8. The mold defined in claim 6, and a flexible liner overlying the mold bottom plate, having edge portions received between the bottom plate edge flanges and the lower side plate flanges including a pair of coplanar parallel band portions, and having a central portion bulged upwardly above such pair of coplanar parallel band portions. 